1. Field of the Invention
The present invention relates to heat dissipating apparatuses and methods for their production, and more particularly to a heat dissipating apparatus having a heat pipe integrally embedded in a heat sink.
2. Description of Related Art
A computer central processing unit (CPU) is the core administrator of electrical signals in most contemporary personal computers. Continued development of CPUs has enabled them to perform more and more functions. Heat generated by CPUs has increased commensurately. If excessive heat is generated, this can adversely affect the operational stability of the CPU and the computer. Measures must be taken to efficiently remove the heat from the CPU.
In the electronics industry, the heat pipe is a relatively recent innovation. The heat pipe utilizes a working material""s phase changes to absorb heat and release heat. The heat pipe is a vacuum-tight vessel partially filled with the working material. The working material is typically water, alcohol or ammonia, and functions as a heat carrier medium. When the heat carrier medium in an evaporation area of the heat pipe is heated by heat generated from the CPU, the phase of the heat carrier medium changes from liquid to vapor. By such phase change, the heat carrier medium absorbs a certain amount of the heat. Then the vapor flows along the heat pipe to a condensation area thereof. The vapor condenses back to a liquid phase by giving up its latent heat of vaporization. Such heat is transferred to an adjoining heat dissipating means such as fins of a heat sink. The liquid flows back to the evaporation area by force of gravity. Internal wicking structures may be used to facilitate the flow of liquid back to the evaporation area by way of capillary action. At the evaporation area, the heat carrier medium then repeats the cycle of removing heat generated from the CPU.
A conventional heat-pipe radiator, as shown in Taiwan Patent No. 86212279, uses two parts of a heat dissipation means to clip a heat pipe device therebetween. Each said part forms several hooks engaging with the other part. The heat pipe is sandwiched between said two parts. Over time, the engagement between said parts progressively weakens. Contact between the heat pipe and said parts loosens, thus reducing the thermal contact area therebetween. This reduces the heat dissipation efficiency of said parts.
Taiwan Patent No. 88114649 discloses a method for producing a heat dissipating device. The heat dissipating device comprises two symmetric heat sinks and a heat pipe sandwiched therebetween. The heat sinks are made by die-casting, and the heat pipe is made separately. The heat sinks are then clipped around the heat pipe to each other with screws. Production of these separate parts and subsequent assembly thereof is unduly complicated, time-consuming and costly.
Accordingly, an object of the present invention is to provide a heat dissipating apparatus having a heat pipe integrally embedded in a heat sink for enhanced thermal conductivity.
Another object of the present invention is to provide a heat dissipating apparatus which is easily molded and easily manufactured.
A further object of the present invention is to provide a method for manufacturing a heat dissipating apparatus which integrally combines a heat pipe and a heat sink together.
In order to achieve the objects set out above, a heat dissipating apparatus of the present invention includes a heat pipe and a heat sink. The heat sink is made by die-casting, and includes a chassis and a plurality of fins extending upwardly from the chassis. The heat-pipe is U-shaped, and is embedded in the heat sink in intimate contact with the chassis and the fins. The heat pipe includes a first end and a second end. The first end is partially embedded in the chassis of the heat sink, for transfer of heat from the chassis to the first end by way of vaporization of working medium in the heat pipe. The second end is embedded in upper portions of the fins, for transfer of heat from the heat pipe to the fins by way of condensation of the vaporized working medium.
Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: